Instead, count how many consecutive times the entry has been found to be
unused and delete it once that count exceeds a limit. This will prevent
excessive reallocating of extradata ID's in applications like folding.
This makes the internal juggling of fold data even more complicated, but
it has a number of advantages:
- Folds will preserved even when opening the file with Aegisub builds
that don't know about folding.
- Folds will be preserved by automation scripts that re-insert every
line.
- Folds do not break when adding or deleting lines in a text editor or
some other editor, as long as the lines involving folds aren't
touched.
- In particular, merging changes using tools like git will not break
folds.
- Copy/pasting folds also keeps the folds to some extent. This is
impossible to solve in full generality, but simple cases like
cut/pasting a folded section somewhere else work, as long as the file
isn't saved in between.
- This will give automation scripts full access to folding without
needing to set up any additional API functions.
Line folds are managed using metadata of AssDialogue elements, and
saved in the project properties. They only affect the appearance of the
subtitle grid, and have no impact on other line operations.
Remove it from the script info section and put it in its own section
that isn't tracked by undo and make it not stringly typed. Removes the
need for the gross hack where changes are slipped in just before saving
to circumvent the undo system, cuts down on the uses of string literals
to identify fields, and probably improves performance a little.
iterator_to requires that the object be in the list, which is sometimes
not the case when processing a commit which removed the active line or a
selected line. To handle this, add a checked version that returns
Events.end() when it is not in the list rather than crashing.
The grid needs to be able to map AssDialogue * to a row number, and just
storing it in the AssDialogue is nearly strictly better than a std::map
mapping events to rows. Probably will be of use elsewhere as well.
